In a medical environment, to draw blood from or inject fluid to a patient, in the case of a syringe being used, conventionally a needle is mated to the syringe by way of a hub to which the needle is attached or integrated. Depending on the procedure, the gauge of the needle tends to vary. It is well established that the gauge of the needle may be determined by the color of the hub. Yet the needle hub, or at least a portion thereof, is often hidden by the needle sheath that covers the needle when the needle is mated to the luer of the syringe.
With current technological and safety advances, a needle protective housing may be attached to the needle hub, with the needle hub, or base, and the needle protective housing being joined and either acting as an adapter as taught by U.S. Pat. No. 4,982,842, or as a single unit with the needle integrated to the base and the needle protective housing connected to the base as disclosed in U.S. Pat. No. 5,993,426 and U.S. Pat. RE37,110. There are also instances where a needle protective housing may be connected to a syringe, as disclosed by U.S. Pat. Nos. 5,232,455, 6,582,397, and application Ser. Nos. 10/657,171 and 29/189,589, both filed on Sep. 9, 2003. The respective disclosures of the '842, '426, '110, '455, and '397 patents and the '171 and '589 applications are incorporated by reference herein.
In the devices disclosed by the aforenoted patents as well as in the prior art, there has not been any established scheme that allows a user to readily determine the gauge of the needle she is using. And given that the use of a needle with a particular gauge may well be of import in an emergency situation, there is a need to provide a scheme whereby a user can readily ascertain the gauge of the needle she would like to use without having to directly look at the needle, which oftentimes is difficult since the needle is usually covered by a sheath prior to use.